#include <avr/io.h>
#include <avr/interrupt.h>
#include <util/delay.h>

ISR(INT2_vect)
{
  while(1){
   for ( int i=8;i>=0;i--)
    {
      PORTA = (1<<i);
      _delay_ms(500);
    }
    sei();
  }
}
ISR(INT3_vect)
{
  while(1){
 for ( int i=0;i<8;i++)
    {
      PORTA = (1<<i);
      _delay_ms(500);
    }
    sei();
  }
  
}


int main (void)
{
  DDRA = 0xff;
  DDRB |=(1<<PB7);// LED output enable
  PORTD |=_BV(PD2);  // pin int0 PD0 pullup
  PORTD |=_BV(PD3);  // pin int0 PD0 pullup
  EIMSK |=(1<<INT2)|(1<<INT3);   // enable interrupt
  EICRA |=_BV(ISC01)|_BV(ISC00)|_BV(ISC10)|_BV(ISC11); //falling edge activate INT0
  sei();
  while (1){
    PORTA=0x00;
    for (unsigned char i=0;i<8;i++)
    {
      PORTA = (1<<i);
      _delay_ms(500);
    }

  }
}